package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdworker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;


/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdworker redisIdworker;
    @Resource
    private IVoucherOrderService voucherOrderServiceProxy;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKIL_SCRIPT;

    static {
        SECKIL_SCRIPT = new DefaultRedisScript<>();
        SECKIL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKIL_SCRIPT.setResultType(Long.class);
    }

    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    private class VoucherOrderHandler implements Runnable {
        @PostConstruct
        public void init() {
            SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
        }

        @Override
        public void run() {
            while (true) {
                try {
                    // 1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create("stream.orders", ReadOffset.lastConsumed())
                    );
                    // 2.判断订单信息是否为空
                    if (list == null || list.isEmpty()) {
                        // 如果为null，说明没有消息，继续下一次循环
                        continue;
                    }
                    // 解析数据
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    // 3.创建订单
                    createVoucherOrder(voucherOrder);
                    // 4.确认消息 XACK
                    stringRedisTemplate.opsForStream().acknowledge("s1", "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    //处理异常消息
                    handlePendingList();
                }
            }
        }
        private void handlePendingList() {
            while (true) {
                try {
                    // 1.获取pending-list中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create("stream.orders", ReadOffset.from("0"))
                    );
                    // 2.判断订单信息是否为空
                    if (list == null || list.isEmpty()) {
                        // 如果为null，说明没有异常消息，结束循环
                        break;
                    }
                    // 解析数据
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    // 3.创建订单
                    createVoucherOrder(voucherOrder);
                    // 4.确认消息 XACK
                    stringRedisTemplate.opsForStream().acknowledge("s1", "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理pendding订单异常", e);
                    try{
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            }
        }
    }


//
//    private void handleVoucherOrder(VoucherOrder voucherOrder) {
//        //获取用户
//        Long userId = voucherOrder.getUserId();
////        创建锁对象
//        RLock lock = redissonClient.getLock("order:" + userId);
//        //获取锁
//        boolean islock = lock.tryLock();
//        if (!islock) {
//            //获取锁失败，直接返回失败或者重试
//            log.error("不允许重复下单");
//            return;
//        }
//        //获取代理对象
//        try {
//            proxy.createVoucherOrder(voucherOrder);
//        } finally {
//            //释放锁
//            lock.unlock();
//        }
//    }


    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        Long orderId = redisIdworker.nextId("order");
        //执行lua脚本
        Long result = stringRedisTemplate.execute(SECKIL_SCRIPT, Collections.emptyList(), voucherId.toString(), userId.toString(), String.valueOf(orderId));
        //判断结果是否为0
        if (result.intValue() != 0) {
            //不为0，代表没有购买资格
            return Result.fail(result == 1 ? "库存不足" : "不能重复下单");
        }
        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //返回订单id
        return Result.ok(orderId);
    }

//@Override
//    public Result seckillVoucher(Long voucherId) {
//        //1、查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            //尚未开始
//            return Result.fail("秒杀尚未开始");
//        }
//        //判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            //已经结束
//            return Result.fail("秒杀已经结束");
//        }
//        //判断库存是否充足
//        if (voucher.getStock() < 1) {
//            //库存不足
//            return Result.fail("库存不足");
//        }

//        Long userId = UserHolder.getUser().getId();
////        synchronized(userId.toString().intern()) {
//
//        //创建锁对象
////        //SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
////        RLock lock = redissonClient.getLock("order:" + userId);
//        //获取锁
//        boolean islock = lock.tryLock();
//        if (!islock) {
//            //获取锁失败，直接返回失败或者重试
//            return Result.fail("不允许重复下单");
//        }
//        //获取代理对象
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } finally {
//            //释放锁
//            lock.unlock();
//        }
//        //return voucherOrderServiceProxy.createVoucherOrder(voucherId);

    /// /        }
//    }
    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();

        //查询订单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //判断是否存在
        if (count > 0) {
            //用户已经购买过
            log.error("用户已经购买过一次");
            return;
        }
        //扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0)
                .update();
        if (!success) {
            //扣减库存失败
            log.error("库存不足");
            return;
        }
        //创建订单
        save(voucherOrder);
    }
}
